1. Field of the Invention
The present invention relates to connectors for releasably joining optical fibers, electrical conductors or other conducting elements, and more particularly to connectors designed for underwater and other difficult applications in which a male member is coupled to an opposing female member to provide coupling of one or more optical fibers, electrical conductors or other conducting elements with relatively close precision.
2. History of the Prior Art
Various connectors are known in which one or more conductors within a first member are coupled to one or more corresponding conductors within a mating second member in releasable fashion. The conductors may be of the optical fiber type in which it is desired to couple opposite lengths of optical fiber. The conductors may also be of the electrical type in which opposite wires are to be coupled together. In still other instances the conductors may comprise fluid conduits which are to be joined together such as in a hydraulic or pneumatic system.
Connectors of such varying types typically involve certain common goals including in particular the ability to couple and uncouple the opposite mating members of the connector with relative ease and in a fashion providing for relatively precise fit and alignment. In particular, it is often desirable to make the opposing members of the connector self-mating in the sense that the members are easily aligned to achieve the coupling, are generally symmetrical at various different relative angles and effect interconnection therebetween in a manner which is assisted by mechanical, magnetic or other devices to facilitate ease of connection. Such features are of particular importance in difficult environments such as underwater applications where ease of connection becomes of paramount importance. A diver wearing heavy gloves or a pressure suit, for example, will frequently have a difficult time effecting coupling of the mating members of a connector which is otherwise relatively simple and easy to operate in air or in other less challenging environments. Similar considerations apply where a robot is employed to operate such connectors in underwater or other difficult environments.
The problems of providing an easily operated connector for underwater or other difficult applications are particularly acute in the case of optical fiber connectors where the conductors to be joined comprise opposite lengths of optical fiber positioned centrally within the opposing members of the connector. Optical fiber connectors may be of the fiber-to-fiber type in which opposite lengths of optical fiber are disposed adjacent and in alignment with one another upon making of the connection. Connectors of this type require extreme accuracy which is difficult to achieve when single fibers are being connected and is even more difficult to achieve when multiple fibers are involved. In a second approach the opposite mating members are provided with quarter pitch self-focusing lenses which provide an expanded beam in the form of a collimator. Such an arrangement is far more tolerant of variations in the distance between the lenses. In a still further approach a half pitch lens is used. Such approach requires rather precise positioning of the lens face relative to adjacent fibers, making this approach impractical for all but a few connector applications. Further problems are created because of such things as different water refraction between the fiber optical fibers and the lenses, impairment of lens surfaces by sea water and insertion loss variations. Oils and jellies have been used to provide index matching between fibers and lenses, with limited success.
Examples of optical fiber connectors using lenses at the interface between opposite mating members are provided by a paper by Dennis M. Knecht and W. John Carlsen entitled "Expanded Beam Fiber Optic Connectors" and by various brochures of Nippon Sheet Glass Company, Ltd. The article by Knecht and Carlsen describes an optical fiber connector in which alignment and certain other tolerances are relaxed through use of a molded lens insert and the elastomeric fiber guides. The brochures of Nippon Sheet Glass Company, Ltd. describe connectors using quarter pitch self-focusing lenses which form an expanded beam or collimator.
Various arrangements of connectors have been provided in an attempt to improve the characteristics of connectors of the optical fiber, electrical or similar type. One example is provided by U.S. Pat. No. 3,786,391 of Mathauser which shows an electrical connector utilizing permanent magnets in opposing male and female connector halves. While the Mathauser patent suggests the concept of utilizing magnetic pole alignment to aid in aligning the electrical contacts, the patent does not relate to or contemplate the type of connector configuration required for underwater or other difficult environments and in particular a connector of that type that would be self-mating. Still further examples of connectors using magnetic or other devices to facilitate connection are provided by U.S. Pat. Nos. 4,112,941 of Larimore, 4,025,964 of Owens, 3,810,258 of Mathauser, 2,170,287 of Kinnebrew, 2,226,287 of Miller and 2,347,023 of Beechlyn.
Still further examples of connectors are provided by a brochure of Crawford Fitting Company describing "Swagelok QUICK-CONNECTS". The connectors described therein which are of the type used to couple together fluid conduits employ arrangements in conjunction with a spring-loaded sleeve to provide for relatively quick and easy connection and disconnection.
The various connectors of the prior art which have been described provide features and advantages in an effort to realize connectors which are relatively easy and simple to use and which at the same time provide in many instances a relatively positive and precise fit or interconnection between the opposing mating members. However such connectors do not provide and do not suggest how to provide certain desired features in connectors designed for use in underwater and certain other difficult applications. In particular, it would be desirable to provide a connector designed for use in underwater or other difficult applications in which the connector is essentially self-mating so as to effect the intercoupling therebetween in a manner assisted by magnetic or other devices so as to greatly simplify the manual operation thereof. It would furthermore be desirable that such connector facilitate easy insertion of the male member into an opposing mating female member in a fashion which makes the connector self-aligning in nature and which makes the connector essentially symmetrical through various different ranges of relative angular position. Of particular advantage would be the provision of a mechanical latching arrangement functioning in conjunction with a magnetic or other arrangement for facilitating movement of the opposing members of the connector into the coupled position so as to tend to hold the members in such position in a manner which resists inadvertent or unwanted uncoupling thereof.